Energy-recuperating lifting jack



Nov. 7, 1961 L. JAVOIRIK ENERGY'RECUPERATING LIIFTING JACK Filed Dec. 9,1959 Fig.1

2 Sheets-Sheet 1 F ig 2 Fig? INVENTOR. Lasz/o Javorilr HIS ATTORNEY$Nov. 7, 1961 JAVORIK 3,007,676

ENERGY-RECUPERATING LIFTING JACK Filed Dec. 9, 1959 2 Sheets-Sheet 2 a KINVENTQR. F g; 5 Lasz/o Javonk BY HIS ATTORNEYS United States Patent3,007,676 ENERGY-RECUPERATING LIFIING JACK Laszl Javorik, 378 N. HamlinSt., Chicago 24, Ill.,

assignor of one-half to Addison W. Arthurs, Pittsburgh, Pa. I

Filed Dec. 9, 1959, Ser. No. 858,512 3 Claims. (Cl. 254-1) Thisinvention relates to an energy-recuperating lifting jack comprising anelevating member and springs connected to the elevating member andadapted to be compressed upon lowering of the elevating member, andmeans for releasably holding the elevating member against the action ofthe spring. The energy-recuperating jack may be loaded in any convenientplace, such as a garage of -a home, by compressing the springs to storeenergy in them. The elevating member of the energy-recuperating jack isheld in lowered position by some suitable means, such as a detent, afterthe spring is loaded. The loaded energy-recuperating jack may then becarried in the automobile and is available for use on the road. Inchanging a tire, for instance, the loaded energy-recuperating liftingjack is placed under the car and the detent, which holds down theelevating member, is released, whereupon the springs which have beenloaded previously expand and supply their energy for raising theautomobile.

The energy-recuperating lifting jack of the present invention can beused for any purpose in which the jack is loaded in a previous operationand the energy of the loaded jack is employed in a subsequent operation.

In the accompanying drawings which illustrate two embodiments of myinvention;

FIGURE 1 is a vertical section of one embodiment showing the elevatingmember of the jack in raised position;

FIGURE 2 is a view similar to FIGURE 1 except that it shows theelevating member in lowered position and the springs compressed;

FIGURE 3 is a vertical section taken on the line IIIIII of FIGURE 2;

FIGURE 4 is a front elevation of another embodiment of the inventionshowing the elevating member in lowered position; and

FIGURE 5 is a vertical section taken on the line VV of FIGURE 4.

Referring more particularly to the accompanying drawings and for thepresent to the embodiment shown in FIGURES 1, 2 and 3, theenergy-recuperating jack comprises a base 2 and an upwardly extendingguide 4 secured at its lower end to the base. This guide may be in theform of a tube. A rack bar 6 having a lifting head 8 at its upper endhas its lower part slidably received in the guide 4. The rack bar isprovided with teeth 10 which are accessible from the outside of theguide 4 due to the provision of a suitable slot 11 in the guide.

Two springs indicated generally by reference numerals 12 and 14 areprovided, each of which is pivotally connected by a pin 16 to a plate 18secured to the base 2 and pivotally connected by a pin 20 to a plate 22secured to the rack bar 6. The plate 22 extends through slots 24 formedin the guide 4 so that the rack bar 6 can move upwardly and downwardlyin the guide. Each of the springs 12 and 14 is made of alternate rubberdiscs 26 and steel discs 28 secured by any suitable means or byvulcanization, such as a suitable cement. Since the springs act almostentirely in compression, a strong bond is not required between therubber discs and the steel discs.

A detent 30 is pivotally mounted by a pin 32 on lugs 34 secured to theguide 4. The lower end 35 of the detent extends into slot 11 and iscaused to engage the teeth 10 of the rack bar 6 by means of acompression spring 36 3,007,676 Patented Nov. 7., 1961 connected to theupper end 38 of the detent and to the guide 4.

i A lever '40, which, in the form illustrated, is a socket for receivingan extention bar, is pivotally mounted by a pin 42 to lugs 44 secured tothe guide 4. A pawl 46 is pivotally connected by a pin 48 to a lug 46aon the lower side of thelever 40. A spring 50 is connected to the lever40' and to the upper end. 52 of the pawl 46. The lower end 54 of thepawl can be brought into engagement with the teeth 10 of the rack bar 6and upon rotation of the lever 40 in a clockwise direction as viewed inFIG- URE 3, the rack bar 6 can be lowered a further amount and thesprings 12 and 14 can be compressed to a further extent than thatobtained by applying a weight to the lifting head 8 if that is required.

A projection 56 is secured to the upper side of. the lever 40with theupper end of the projection in a position to contact the detent 30 andrelease it from the teeth 10 when the lever '40 is rotatedcounterclockwise from the position shown in FIGURE 3.

In preparing the jack for use, it is preloaded by applying a downwardforce on the lifting head 8, thereby lowering the rack bar 6 andcompressing the springs 12 and 14. The rack bar is held in its loweredposition by the detent 30. When it is desired to use the preloaded jackin lifting a weight, the head 8 is placed under the weight to be liftedand the lever 40 is rotated counterclockwise so that the projection 56engages the detent 30, thereby releasing it. The pawl 46 also isreleased from teeth 10, whereupon the springs 12 and 1 4 expand to raisethe rack bar 6.

Referring now to the embodiment shown in FIGURES 4 and 5, the jackcomprises a base 60 to which is secured a guide 62 in the form of atube. The guide 62 slidably receives a rack bar 64 having a lifting head66 secured to it.

The upper ends of each of two links 68 are pivotally connected by pins70 to the lifting head 66 and the lower ends of each of two links 72 arepivotally connected by pins 74 to the base 60. The adjacent ends of thelinks 68 and 72 are pivotally connected by pins 76 to spring plates 78.Steel coil springs 80 are interposed between the plates 78 and plates 82which are secured to the upturned ends 84 of the base 60. The ends ofthe springs fit into retaining rings 85 secured to the plates 78 and 82.The links 68 and 72 form two linkages located on opposite sides of therack bar 64 and the springs 80 exert their pressure at the knees of thelinkages formed by the pins 76. Two bumpers 86 are secured to the guide62 to limit inward movement of the linkages when the springs 80 areallowed to expand. As shown in FIGURE 4, the links 68 and 72 extend atan angle to the vertical of about 45 degrees. When the springs areallowed to expand, the links 68 are limited in their inward movement bythe bumpers 86 and at this position the links 68 extend at an angle ofabout 10 degrees to the vertical. Thus, the working range of thelinkages is within a range of from about 10 to 45 degrees with respectto the vertical. When the linkages and springs are in the position shownin FIG- URE 4, Le, the links 68 are at an angle of about 45 degrees tothe vertical, the springs 80 exert a powerful force since they aregreatly compressed but the moment arm through which the springs exerttheir force is relatively small whereas when the links '68 have moved totheir innermost position, i.e., the links extend at an angle of about 10degrees to the vertical, the spring force is less but the moment arm isgreater and, on the other hand, the moment arm of the load is less.Thus, the upward force applied by the springs to the lifting head 66 issubstantially constant throughout the working range of the springs.

The remaining construction of the jack shown in FIG- URES 4 and 5 is thesame as that shown in FIGURES 1-3. It has a lever 90 similar to thelever 40, a projection 92 similar to the projection 56, a pawl 94similar to the pawl 46 and a detent 96 similar to the detent 30 togetherwith a spring 98 similar to the spring 50 and a spring 100 similar tothe spring '36. The embodiment shown in FIGURES 4 and 5 is usedsubstantially in the same manner as the embodiment shown in FIGURES 13In each of the embodiments, the pawl 46 shown in FIGURE 3 and the pawl94 shown in FIGURE 5 can be dispensed with in those cases where it isnot desired to provide means for compressing the springs 12 and 14 orthe springs 80 to an extent beyond that which is obtained by applying aforce or weight to the lifting heads 8 or 66.

The invention is not limited to the preferred embodiments but may beotherwise embodied or practiced within the scope of the followingclaims.

I claim:

1. An energy-recuperating jack comprising a base, a guide secured to andextending upwardly from said base, a rack slidable in said guide andhaving a lifting head, toggle linkages located at opposite sides of saidrack and comprising pairs of links pivotally connected to each other toform knees, each of said linkages being pivotally connected at one endto said base and at its opposite end to said lifting head, springsconnected to said base and pivotally connected to each of said linkagesat said knees and arranged to exert an upward component of force on saidrack when they are compressed, and a detent pivoted to said guide andadapted to engage said rack to prevent it from rising under the actionof said springs.

2. A jack according to claim 1, wherein said springs are steel springs.

3. A jack according to claim 2, wherein said links in operation movebetween an angle of about 10 degrees and an angle of about degrees tothe vertical.

References Cited in the file of this patent UNITED STATES PATENTS727,192 Payne May 5, 1903 FOREIGN PATENTS 3,306 Great Britain 1908208,023 Great Britain Dec. 13, 1923

